1. Field of the Invention
Embodiments of the present invention relate to an electronic stringed instrument and, in particular embodiments, to an electronic stringed instrument in which the pitch and envelope level are detected and the instrument is controlled so as to form a new musical tone that conforms to the pitch and the envelope level.
2. Related Art
In Japanese Laid-Open Patent Application Publication (Kokai) Number Hei 7-110687 (Patent Reference 1) a pitch information detection system is disclosed that detects the vibrations of the strings of an electronic stringed instrument and the like with a pick-up and, using a DSP (digital signal processor), digitally carries out the detection of the pitch. In an electronic stringed instrument such as a guitar synthesizer that has the pitch information detection system that is cited in Patent Reference 1, the tone generator is driven based on the pitch information that has been detected by the pitch information detection system and the envelope level of the string vibrations, and the generation of a new musical tone is carried out in accordance with that.
However, with an electronic stringed instrument that has the pitch information detection system cited in Patent Reference 1, when a specific string is pressed at a fret and the sound is produced, if the finger is released from the fret, the vibration of the string is terminated and the pitch drops slightly at that moment. This is because when the string has been pressed onto the fret, the string vibrates with the fret as the endpoint node but in the instant that the string disengages from the fret when the finger is released from the fret, the finger that is in contact with the string becomes the endpoint node.
Accordingly, an electronic stringed instrument such as that described above detects the fact that the pitch has dropped and the pitch of the musical tone that is produced by the tone generator also is lowered. Because the envelope level suddenly becomes lower when the finger is released from the fret, in those cases only the vibration of the string is emitted as the musical tone, even if there is some degree of a drop in the musical interval, it does not become a problem; but in the case of a guitar synthesizer in which the sound generation is in conformance with the pitch that has been detected, there are instances where the attenuation of the envelope level is dampened after the termination of the musical tone has been instructed and since, when there is a dampened attenuation of the envelope level in a state in which the note height has become low, the vibration of the string is different from the desired pitch, there is a feeling of incompatibility. In particular, when the finger is released in a case such as when the performance is done with chords, since for each string, there is a drop in the pitch that is different for each, there has been a problem in that the harmonization of the chords cannot be done.